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SKU: 040005 / UPC: 63206084
GrimmSpeed Hella Horn Wiring Harness for 2002-2014 Subaru WRX and STI – Plug-and-Play Upgrade for Clear, Powerful Sound
Yhe GrimmSpeed Hella Horn Wiring Harness, designed specifically for 2002-2014 WRX and STI models. This pre-assembled harness delivers a direct connection to Hella horns, ensuring full volume output without the clutter of extra relays or fuses. Built with automotive-grade materials, it connects seamlessly to your factory wiring in under a minute, providing a factory-like finish that withstands daily driving demands.
Precise Vehicle Fitment
This harness fits a wide range of Subaru models from the early 2000s, confirmed through extensive testing on GD, GR, and VA chassis platforms. Compatible vehicles include:
- Subaru Impreza (2002-2012): All trims, including base, WRX, and WRX STI variants.
- Subaru WRX (2002-2014): Sedan and hatchback models, covering standard WRX, WRX Limited, WRX Premium, and WRX TR editions.
- Subaru WRX STI (2004-2014): All STI models, including STI Limited and STI Special Edition.
- Subaru Forester (2003-2008): Base, X, XS, XT, and XT Limited trims.
- Subaru Legacy (2002-2015): 2.5i, 2.5GT, 3.0R, 3.6R, GT, and GT spec.B models, including Limited and Premium variants.
- Subaru Outback (2002-2015): 2.5i, 3.0R, 3.6R, Base, H6, XT, and XT Limited editions, covering L.L. Bean and VDC configurations.
Verify your exact year, make, and model using the Subaru VIN decoder or consult your owner's manual for confirmation.
What's Included in Your Purchase
Every order includes:
- (1) Pre-assembled GrimmSpeed Hella Horn Wiring Harness with 16-gauge automotive-grade wire for low-resistance power delivery.
- Heat-shrink crimp terminals for secure, weather-resistant connections.
- Protective black nylon sleeving to guard against abrasion, heat, and mechanical stress.
- OEM-style plug connectors for instant integration with factory harness no cutting, splicing, or soldering required.
Part Number: 040005 (also listed as GRM040005)
UPC: 63206084
Key Specifications and Build Details
- Wire Gauge: 16 AWG, tinned copper for corrosion resistance and maximum current flow to achieve peak horn decibel levels.
- Terminals: Insulated heat-shrink design prevents shorts and ensures long-term reliability in engine bay conditions.
- Sleeving: Durable braided nylon exterior for a professional, tucked-away appearance.
- Installation: True plug-and-play routes cleanly behind the core support and mates directly to Hella horn leads and OEM horn circuit.
- Relay Option: Ships without a relay for simplicity (testing shows negligible volume gain from relays, reducing failure risks); easily modifiable to add one if preferred.
- Item Weight: Approximately 0.5 lbs (lightweight design minimizes added mass).
- Shipping Box Dimensions: 6 inches (L) x 2 inches (W) x 5 inches (H).
- Shipping Weight: Approximately 4 lbs.
Why This Harness Stands Out for Subaru Owners
Drivers choose the GrimmSpeed Hella Horn Wiring Harness because it eliminates the guesswork of custom wiring jobs that often lead to weak signals or intermittent failures. Paired with Hella Supertone horns, it produces a sharp, penetrating 118-118 dB dual-tone alert that's audible over traffic far beyond stock Subaru horns while keeping your engine bay organized. No more muffled sounds or exposed wires, this setup handles rain, road salt, and vibrations without faltering. Thousands of WRX and STI enthusiasts rely on it for its straightforward install and consistent performance, making it the straightforward pick for anyone serious about safety and sound on the road.
Ready to hear the difference? Add the GrimmSpeed Hella Horn Wiring Harness (SKU 040005) to your cart today and experience reliable horn power tailored for your Subaru.
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